The Spatial Distribution and Evolution Characteristics of North Atlantic Cyclones

H. F. Dacre, S. L. Gray
2009 Monthly Weather Review  
The composite evolution of west and east Atlantic cyclone is likely to be different as they develop in different environmental conditions. • East Atlantic cyclones develop faster than west Atlantic cyclones and have lower mslp, this may be due to the existence of a preexisting parent cyclone in the vicinity of the cyclone. • West Atlantic cyclones have higher low-level PV, this may be generated by friction in the boundary layer or latent heat release. • The ratio of upper-to lower-level qg
more » ... lower-level qg forcing is lower for west Atlantic cyclones due to a larger contribution from low-levels. Conclusions • The thermodynamic method of cyclone identification locates more cyclone features than previous methods. • Most cyclones that reach the UK originate in the east Atlantic where baroclinicity and SST gradients are weak. • East Atlantic cyclones have stronger relative vorticity and lower mslp at their genesis point, consistent with secondary cyclogenesis. • East Atlantic cyclones develop faster, have very weak low-level forcing and strong upper-level forcing.
doi:10.1175/2008mwr2491.1 fatcat:3joq23nq3jar5mwepuqxcr4jwi